1. Field of the Invention
This invention relates generally to magnetic tape recording and/or reproducing apparatus, and more particularly is directed to an improved device by which such apparatus can be automatically operated in response to the reception of a call by an associated telephone or actuation by a timer to either record a telephone message or to reproduce a recorded message or musical sounds and thereby provide an alarm.
2. Description of the Prior Art
Magnetic tape recording and/or reproducing apparatus is usually provided with an operating mode selecting device which includes a plurality of push-buttons that are selectively actuable from rest positions to active positions for selecting respective operating modes of the apparatus. For example, the mode selecting device may include a push-button actuable to select a fast-forward operating mode, a push-button actuable to select a normal-forward operating mode for either reproducing or recording operations, a push-button actuable to select a rewind operating mode, and a push-button actuable for returning the recording and/or reproducing apparatus from any one of the previously mentioned operating modes to a stop or neutral condition. Further, the mode selecting device usually includes a recording push-button which, when actuated simultaneously with the normal-forward push-button, selects the recording operating mode, while actuation of the normal-forward push-button alone selects the reproducing mode of operation.
The existing mode selecting devices are either of the so-called locked push-button type or the non-locked push-button type. In devices of the locked push-button type, each operating mode selecting push-button, when displaced to its active position, is mechanically locked or latched in such active position to maintain the selected operating mode or condition of the apparatus until another of the operating mode selecting push-buttons or the stop push-button is actuated, whereupon the mechanical lock or latch is released to permit return of the previously displaced push-button to its rest position.
In devices of the non-locked push-button type, each of the mode selecting push-buttons, when displaced to its active position is free to be spring-urged back to its rest position as soon as the manually exerted pressure for displacing the push-button is removed from the latter. When any one of the mode selecting push-buttons is temporarily displaced to its active position for momentarily closing a respective switch, a control circuit is conditioned for establishing the respective operating mode and the control circuit is electrically maintained or held in such condition, even though the push-button returns to its rest position, until such time as either the stop push-button is actuated or another of the operating mode selecting push-buttons is actuated to cause the control circuit condition to be altered for establishing another operating mode of the apparatus. Mode selecting devices of the non-locked push-button type, as aforesaid, are advantageous in that only a relatively light force need be applied to any one of the mode selecting push-buttons for momentarily displacing the same and thereby initiating the respective operating mode of the recording and/or reproducing apparatus.
Frequently, it is desired to employ a magnetic tape recording and/or reproducing apparatus, as above, for automatically recording a message received by way of an unattended telephone, or for automatically reproducing music or other sound recorded on a tape in response to the operation of an associated timer, for example, to provide an alarm. When the recording and/or reproducing apparatus has a mode selecting device of the locked push-button type, its automatic recording or reproducing operation, as aforesaid, is made possible by interposing a normally open automatic control switch between the power supply for the apparatus and the drive circuit for the latter, and by effecting automatic closing of such control switch either in response to the reception of a call by the associated telephone when the latter is unattended, or in response to the expiration of a predetermined time period set on a suitable timer. In preparing the apparatus for automatic recording or reproducing operation, each push-button for selecting the respective mode of operation is displaced to its active position where it is locked mechanically to establish the conditions for such mode of operation in the drive circuit even though the latter is not energized by reason of the open condition of the automatic control switch. Thereafter, when the automatic control switch is closed to supply power to the drive circuit, for example, in response to the reception of a call by the associated unattended telephone or the operation of the timer, the apparatus performs a recording or reproducing operation which, in the case of the recording of a telephone message, is discontinued when the control switch returns to its open condition at the conclusion of the call even though each previously displaced push-button of the mode selecting device remains locked in its active position.
However, if the magnetic tape recording and/or reproducing apparatus has a mode selecting device of the non-locked push-button type, the mere interposing of the automatic control switch between the power supply and the control circuit of the apparatus will not be sufficient to adapt the apparatus for the subsequent automatic recording of a message received by an unattended telephone which causes closing of the automatic control switch when a call is received, or for the subsequent automatic reproducing of recorded sounds as an alarm when the automatic control switch is closed by an associated timer. This will be seen from the fact that, if the automatic control switch is open so that the control circuit is not energized at the time when the recording push-button and/or the normal-forward push-button is momentarily displaced to the active position thereof, the control circuit will not be electrically held or maintained in the condition for a recording or reproducing operation, respectively. Thereafter, when the automatic control switch is closed, the control circuit will be and remain, in the condition for the stop mode, and neither a recording or reproducing operation will occur.
Accordingly, when adopting a recording and/or reproducing apparatus having a mode selecting device of the non-locked push-button type for the described automatic operation, it has been the practice to employ, in addition to the automatic control switch between the power supply and the control circuit, a strip of adhesive tape or the like by which the non-locked push-buttons for selecting the recording or reproducing modes of operation can be held in their active positions. Applying such adhesive tape to the mode selecting device when setting up the apparatus for automatic recording or reproducing operations is obviously bothersome, as is the removal of such tape from the mode selecting device when it is desired to return to normal control of the operations by selective actuation of the push-buttons. In order to avoid the obvious disadvantages of the use of adhesive tape, as aforesaid, it has been proposed to provide the apparatus having a mode selecting device of the non-locked push-button type with a separate or additional remote control unit. Such remote control unit includes circuits which are connected in parallel with the switches controlled by the non-locked push-buttons of the mode selecting device for selecting the recording and reproducing modes of operation with each of those circuits in the remote control unit having a respective manually actuable switch which remains, or is mechanically locked in its closed position after being displaced thereto and which is in series with a timer or telephone actuated automatic control switch.
With a remote control unit as described above, the manually actuable switch of the circuit thereof in parallel with, for example, the switch actuable by the normal-forward push-button of the regular mode selecting device, may be displaced to its active position to subsequently condition the apparatus for a reproducing operation when the automatic control switch of the remote control unit is closed, for example, by an associated timer. Once the reproducing operation is initiated by the timer, as aforesaid, such operation cannot be halted by actuation of the stop push-button of the regular mode selecting device, nor can any other operating mode of the apparatus be selected by actuation of the respective push-button of the regular mode selecting device until the manually actuable switch of the remote control unit is manually returned from its locked active position to its open position. Therefore, with the described remote control unit, the latter cannot be set to cause the associated recording and/or reproducing apparatus to automatically perform a reproducing operation at the predetermined time each day, as set on the timer, that is, to act as an alarm clock, while the apparatus is normally controllable at all other times by its mode selecting device. Further, although the control circuit of the recording and/or reproducing apparatus is designed to be controlled in response to momentary closing of the switches associated with the non-locked push-buttons of the mode selecting device, the circuits of the remote control unit which are connected in parallel with such switches remain closed for as long as the automatic control switch is closed either in response to a call being received by the associated telephone or in response to operation of the timer, and the foregoing is undesirable in that it may result in deterioration of the components in the control circuit of the recording and/or reproducing apparatus.